4 * Linux Trace Toolkit Control Library
6 * Copyright (C) 2011 David Goulet <david.goulet@polymtl.ca>
8 * This library is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU Lesser General Public License, version 2.1 only,
10 * as published by the Free Software Foundation.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public License
18 * along with this library; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
31 #include <common/common.h>
32 #include <common/defaults.h>
33 #include <common/sessiond-comm/sessiond-comm.h>
34 #include <common/uri.h>
35 #include <common/utils.h>
36 #include <lttng/lttng.h>
37 #include <lttng/health-internal.h>
39 #include "filter/filter-ast.h"
40 #include "filter/filter-parser.h"
41 #include "filter/filter-bytecode.h"
42 #include "filter/memstream.h"
43 #include "lttng-ctl-helper.h"
46 static const int print_xml
= 1;
47 #define dbg_printf(fmt, args...) \
48 printf("[debug liblttng-ctl] " fmt, ## args)
50 static const int print_xml
= 0;
51 #define dbg_printf(fmt, args...) \
53 /* do nothing but check printf format */ \
55 printf("[debug liblttnctl] " fmt, ## args); \
60 /* Socket to session daemon for communication */
61 static int sessiond_socket
;
62 static char sessiond_sock_path
[PATH_MAX
];
65 static char *tracing_group
;
71 * Those two variables are used by error.h to silent or control the verbosity of
72 * error message. They are global to the library so application linking with it
73 * are able to compile correctly and also control verbosity of the library.
76 int lttng_opt_verbose
;
79 * Copy string from src to dst and enforce null terminated byte.
82 void lttng_ctl_copy_string(char *dst
, const char *src
, size_t len
)
85 strncpy(dst
, src
, len
);
86 /* Enforce the NULL terminated byte */
94 * Copy domain to lttcomm_session_msg domain.
96 * If domain is unknown, default domain will be the kernel.
99 void lttng_ctl_copy_lttng_domain(struct lttng_domain
*dst
,
100 struct lttng_domain
*src
)
104 case LTTNG_DOMAIN_KERNEL
:
105 case LTTNG_DOMAIN_UST
:
106 case LTTNG_DOMAIN_JUL
:
107 memcpy(dst
, src
, sizeof(struct lttng_domain
));
110 memset(dst
, 0, sizeof(struct lttng_domain
));
117 * Send lttcomm_session_msg to the session daemon.
119 * On success, returns the number of bytes sent (>=0)
120 * On error, returns -1
122 static int send_session_msg(struct lttcomm_session_msg
*lsm
)
127 ret
= -LTTNG_ERR_NO_SESSIOND
;
131 DBG("LSM cmd type : %d", lsm
->cmd_type
);
133 ret
= lttcomm_send_creds_unix_sock(sessiond_socket
, lsm
,
134 sizeof(struct lttcomm_session_msg
));
136 ret
= -LTTNG_ERR_FATAL
;
144 * Send var len data to the session daemon.
146 * On success, returns the number of bytes sent (>=0)
147 * On error, returns -1
149 static int send_session_varlen(void *data
, size_t len
)
154 ret
= -LTTNG_ERR_NO_SESSIOND
;
163 ret
= lttcomm_send_unix_sock(sessiond_socket
, data
, len
);
165 ret
= -LTTNG_ERR_FATAL
;
173 * Receive data from the sessiond socket.
175 * On success, returns the number of bytes received (>=0)
176 * On error, returns -1 (recvmsg() error) or -ENOTCONN
178 static int recv_data_sessiond(void *buf
, size_t len
)
183 ret
= -LTTNG_ERR_NO_SESSIOND
;
187 ret
= lttcomm_recv_unix_sock(sessiond_socket
, buf
, len
);
189 ret
= -LTTNG_ERR_FATAL
;
197 * Check if we are in the specified group.
199 * If yes return 1, else return -1.
202 int lttng_check_tracing_group(void)
204 struct group
*grp_tracing
; /* no free(). See getgrnam(3) */
206 int grp_list_size
, grp_id
, i
;
208 const char *grp_name
= tracing_group
;
210 /* Get GID of group 'tracing' */
211 grp_tracing
= getgrnam(grp_name
);
213 /* If grp_tracing is NULL, the group does not exist. */
217 /* Get number of supplementary group IDs */
218 grp_list_size
= getgroups(0, NULL
);
219 if (grp_list_size
< 0) {
224 /* Alloc group list of the right size */
225 grp_list
= malloc(grp_list_size
* sizeof(gid_t
));
230 grp_id
= getgroups(grp_list_size
, grp_list
);
236 for (i
= 0; i
< grp_list_size
; i
++) {
237 if (grp_list
[i
] == grp_tracing
->gr_gid
) {
251 * Try connect to session daemon with sock_path.
253 * Return 0 on success, else -1
255 static int try_connect_sessiond(const char *sock_path
)
259 /* If socket exist, we check if the daemon listens for connect. */
260 ret
= access(sock_path
, F_OK
);
266 ret
= lttcomm_connect_unix_sock(sock_path
);
272 ret
= lttcomm_close_unix_sock(ret
);
274 perror("lttcomm_close_unix_sock");
284 * Set sessiond socket path by putting it in the global sessiond_sock_path
287 * Returns 0 on success, negative value on failure (the sessiond socket path
288 * is somehow too long or ENOMEM).
290 static int set_session_daemon_path(void)
292 int in_tgroup
= 0; /* In tracing group */
298 /* Are we in the tracing group ? */
299 in_tgroup
= lttng_check_tracing_group();
302 if ((uid
== 0) || in_tgroup
) {
303 lttng_ctl_copy_string(sessiond_sock_path
,
304 DEFAULT_GLOBAL_CLIENT_UNIX_SOCK
, sizeof(sessiond_sock_path
));
312 ret
= try_connect_sessiond(sessiond_sock_path
);
316 /* Global session daemon not available... */
318 /* ...or not in tracing group (and not root), default */
321 * With GNU C < 2.1, snprintf returns -1 if the target buffer is too small;
322 * With GNU C >= 2.1, snprintf returns the required size (excluding closing null)
324 ret
= snprintf(sessiond_sock_path
, sizeof(sessiond_sock_path
),
325 DEFAULT_HOME_CLIENT_UNIX_SOCK
, utils_get_home_dir());
326 if ((ret
< 0) || (ret
>= sizeof(sessiond_sock_path
))) {
338 * Connect to the LTTng session daemon.
340 * On success, return 0. On error, return -1.
342 static int connect_sessiond(void)
346 /* Don't try to connect if already connected. */
351 ret
= set_session_daemon_path();
356 /* Connect to the sesssion daemon */
357 ret
= lttcomm_connect_unix_sock(sessiond_sock_path
);
362 sessiond_socket
= ret
;
372 * Clean disconnect from the session daemon.
373 * On success, return 0. On error, return -1.
375 static int disconnect_sessiond(void)
380 ret
= lttcomm_close_unix_sock(sessiond_socket
);
389 * Ask the session daemon a specific command and put the data into buf.
390 * Takes extra var. len. data as input to send to the session daemon.
392 * Return size of data (only payload, not header) or a negative error code.
395 int lttng_ctl_ask_sessiond_varlen(struct lttcomm_session_msg
*lsm
,
396 void *vardata
, size_t varlen
, void **buf
)
401 struct lttcomm_lttng_msg llm
;
403 ret
= connect_sessiond();
405 ret
= -LTTNG_ERR_NO_SESSIOND
;
409 /* Send command to session daemon */
410 ret
= send_session_msg(lsm
);
412 /* Ret value is a valid lttng error code. */
415 /* Send var len data */
416 ret
= send_session_varlen(vardata
, varlen
);
418 /* Ret value is a valid lttng error code. */
422 /* Get header from data transmission */
423 ret
= recv_data_sessiond(&llm
, sizeof(llm
));
425 /* Ret value is a valid lttng error code. */
429 /* Check error code if OK */
430 if (llm
.ret_code
!= LTTNG_OK
) {
435 size
= llm
.data_size
;
437 /* If client free with size 0 */
445 data
= (void*) malloc(size
);
447 /* Get payload data */
448 ret
= recv_data_sessiond(data
, size
);
455 * Extra protection not to dereference a NULL pointer. If buf is NULL at
456 * this point, an error is returned and data is freed.
459 ret
= -LTTNG_ERR_INVALID
;
468 disconnect_sessiond();
473 * Create lttng handle and return pointer.
474 * The returned pointer will be NULL in case of malloc() error.
476 struct lttng_handle
*lttng_create_handle(const char *session_name
,
477 struct lttng_domain
*domain
)
479 struct lttng_handle
*handle
= NULL
;
481 if (domain
== NULL
) {
485 handle
= malloc(sizeof(struct lttng_handle
));
486 if (handle
== NULL
) {
487 PERROR("malloc handle");
491 /* Copy session name */
492 lttng_ctl_copy_string(handle
->session_name
, session_name
,
493 sizeof(handle
->session_name
));
495 /* Copy lttng domain */
496 lttng_ctl_copy_lttng_domain(&handle
->domain
, domain
);
503 * Destroy handle by free(3) the pointer.
505 void lttng_destroy_handle(struct lttng_handle
*handle
)
511 * Register an outside consumer.
512 * Returns size of returned session payload data or a negative error code.
514 int lttng_register_consumer(struct lttng_handle
*handle
,
515 const char *socket_path
)
517 struct lttcomm_session_msg lsm
;
519 if (handle
== NULL
|| socket_path
== NULL
) {
520 return -LTTNG_ERR_INVALID
;
523 memset(&lsm
, 0, sizeof(lsm
));
524 lsm
.cmd_type
= LTTNG_REGISTER_CONSUMER
;
525 lttng_ctl_copy_string(lsm
.session
.name
, handle
->session_name
,
526 sizeof(lsm
.session
.name
));
527 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
529 lttng_ctl_copy_string(lsm
.u
.reg
.path
, socket_path
, sizeof(lsm
.u
.reg
.path
));
531 return lttng_ctl_ask_sessiond(&lsm
, NULL
);
535 * Start tracing for all traces of the session.
536 * Returns size of returned session payload data or a negative error code.
538 int lttng_start_tracing(const char *session_name
)
540 struct lttcomm_session_msg lsm
;
542 if (session_name
== NULL
) {
543 return -LTTNG_ERR_INVALID
;
546 memset(&lsm
, 0, sizeof(lsm
));
547 lsm
.cmd_type
= LTTNG_START_TRACE
;
549 lttng_ctl_copy_string(lsm
.session
.name
, session_name
,
550 sizeof(lsm
.session
.name
));
552 return lttng_ctl_ask_sessiond(&lsm
, NULL
);
556 * Stop tracing for all traces of the session.
558 static int _lttng_stop_tracing(const char *session_name
, int wait
)
561 struct lttcomm_session_msg lsm
;
563 if (session_name
== NULL
) {
564 return -LTTNG_ERR_INVALID
;
567 memset(&lsm
, 0, sizeof(lsm
));
568 lsm
.cmd_type
= LTTNG_STOP_TRACE
;
570 lttng_ctl_copy_string(lsm
.session
.name
, session_name
,
571 sizeof(lsm
.session
.name
));
573 ret
= lttng_ctl_ask_sessiond(&lsm
, NULL
);
574 if (ret
< 0 && ret
!= -LTTNG_ERR_TRACE_ALREADY_STOPPED
) {
582 /* Check for data availability */
584 data_ret
= lttng_data_pending(session_name
);
586 /* Return the data available call error. */
592 * Data sleep time before retrying (in usec). Don't sleep if the call
593 * returned value indicates availability.
596 usleep(DEFAULT_DATA_AVAILABILITY_WAIT_TIME
);
598 } while (data_ret
!= 0);
606 * Stop tracing and wait for data availability.
608 int lttng_stop_tracing(const char *session_name
)
610 return _lttng_stop_tracing(session_name
, 1);
614 * Stop tracing but _don't_ wait for data availability.
616 int lttng_stop_tracing_no_wait(const char *session_name
)
618 return _lttng_stop_tracing(session_name
, 0);
622 * Add context to a channel.
624 * If the given channel is NULL, add the contexts to all channels.
625 * The event_name param is ignored.
627 * Returns the size of the returned payload data or a negative error code.
629 int lttng_add_context(struct lttng_handle
*handle
,
630 struct lttng_event_context
*ctx
, const char *event_name
,
631 const char *channel_name
)
633 struct lttcomm_session_msg lsm
;
635 /* Safety check. Both are mandatory */
636 if (handle
== NULL
|| ctx
== NULL
) {
637 return -LTTNG_ERR_INVALID
;
640 memset(&lsm
, 0, sizeof(lsm
));
642 lsm
.cmd_type
= LTTNG_ADD_CONTEXT
;
644 /* If no channel name, send empty string. */
645 if (channel_name
== NULL
) {
646 lttng_ctl_copy_string(lsm
.u
.context
.channel_name
, "",
647 sizeof(lsm
.u
.context
.channel_name
));
649 lttng_ctl_copy_string(lsm
.u
.context
.channel_name
, channel_name
,
650 sizeof(lsm
.u
.context
.channel_name
));
653 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
655 memcpy(&lsm
.u
.context
.ctx
, ctx
, sizeof(struct lttng_event_context
));
657 lttng_ctl_copy_string(lsm
.session
.name
, handle
->session_name
,
658 sizeof(lsm
.session
.name
));
660 return lttng_ctl_ask_sessiond(&lsm
, NULL
);
664 * Enable event(s) for a channel.
665 * If no event name is specified, all events are enabled.
666 * If no channel name is specified, the default 'channel0' is used.
667 * Returns size of returned session payload data or a negative error code.
669 int lttng_enable_event(struct lttng_handle
*handle
,
670 struct lttng_event
*ev
, const char *channel_name
)
672 return lttng_enable_event_with_exclusions(handle
, ev
, channel_name
,
677 * Create or enable an event with a filter expression.
679 * Return negative error value on error.
680 * Return size of returned session payload data if OK.
682 int lttng_enable_event_with_filter(struct lttng_handle
*handle
,
683 struct lttng_event
*event
, const char *channel_name
,
684 const char *filter_expression
)
686 return lttng_enable_event_with_exclusions(handle
, event
, channel_name
,
687 filter_expression
, 0, NULL
);
691 * Enable event(s) for a channel, possibly with exclusions and a filter.
692 * If no event name is specified, all events are enabled.
693 * If no channel name is specified, the default name is used.
694 * If filter expression is not NULL, the filter is set for the event.
695 * If exclusion count is not zero, the exclusions are set for the event.
696 * Returns size of returned session payload data or a negative error code.
698 int lttng_enable_event_with_exclusions(struct lttng_handle
*handle
,
699 struct lttng_event
*ev
, const char *channel_name
,
700 const char *filter_expression
,
701 int exclusion_count
, char **exclusion_list
)
703 struct lttcomm_session_msg lsm
;
704 char *varlen_data
, *jul_filter
= NULL
;
706 struct filter_parser_ctx
*ctx
= NULL
;
709 if (handle
== NULL
|| ev
== NULL
) {
710 return -LTTNG_ERR_INVALID
;
713 /* Empty filter string will always be rejected by the parser
714 * anyway, so treat this corner-case early to eliminate
715 * lttng_fmemopen error for 0-byte allocation.
717 if (filter_expression
&& filter_expression
[0] == '\0') {
718 return -LTTNG_ERR_INVALID
;
721 memset(&lsm
, 0, sizeof(lsm
));
723 /* If no channel name, send empty string. */
724 if (channel_name
== NULL
) {
725 lttng_ctl_copy_string(lsm
.u
.enable
.channel_name
, "",
726 sizeof(lsm
.u
.enable
.channel_name
));
728 lttng_ctl_copy_string(lsm
.u
.enable
.channel_name
, channel_name
,
729 sizeof(lsm
.u
.enable
.channel_name
));
732 if (ev
->name
[0] != '\0') {
733 lsm
.cmd_type
= LTTNG_ENABLE_EVENT
;
735 lsm
.cmd_type
= LTTNG_ENABLE_ALL_EVENT
;
738 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
739 memcpy(&lsm
.u
.enable
.event
, ev
, sizeof(lsm
.u
.enable
.event
));
741 lttng_ctl_copy_string(lsm
.session
.name
, handle
->session_name
,
742 sizeof(lsm
.session
.name
));
743 lsm
.u
.enable
.exclusion_count
= exclusion_count
;
744 lsm
.u
.enable
.bytecode_len
= 0;
747 * For the JUL domain, a filter is enforced except for the enable all
748 * event. This is done to avoid having the event in all sessions thus
749 * filtering by logger name.
751 if (exclusion_count
== 0 && filter_expression
== NULL
&&
752 (handle
->domain
.type
!= LTTNG_DOMAIN_JUL
|| ev
->name
[0] == '*')) {
753 ret
= lttng_ctl_ask_sessiond(&lsm
, NULL
);
758 * We have either a filter or some exclusions, so we need to set up
759 * a variable-length memory block from where to send the data
762 /* Parse filter expression */
763 if (filter_expression
!= NULL
||
764 (handle
->domain
.type
== LTTNG_DOMAIN_JUL
&& ev
->name
[0] != '*')) {
765 if (handle
->domain
.type
== LTTNG_DOMAIN_JUL
) {
768 if (filter_expression
) {
769 err
= asprintf(&jul_filter
, "%s && logger_name == \"%s\"",
770 filter_expression
, ev
->name
);
772 err
= asprintf(&jul_filter
, "logger_name == \"%s\"", ev
->name
);
776 return -LTTNG_ERR_NOMEM
;
778 filter_expression
= jul_filter
;
782 * casting const to non-const, as the underlying function will
783 * use it in read-only mode.
785 fmem
= lttng_fmemopen((void *) filter_expression
,
786 strlen(filter_expression
), "r");
788 fprintf(stderr
, "Error opening memory as stream\n");
790 return -LTTNG_ERR_FILTER_NOMEM
;
792 ctx
= filter_parser_ctx_alloc(fmem
);
794 fprintf(stderr
, "Error allocating parser\n");
795 ret
= -LTTNG_ERR_FILTER_NOMEM
;
796 goto filter_alloc_error
;
798 ret
= filter_parser_ctx_append_ast(ctx
);
800 fprintf(stderr
, "Parse error\n");
801 ret
= -LTTNG_ERR_FILTER_INVAL
;
804 ret
= filter_visitor_set_parent(ctx
);
806 fprintf(stderr
, "Set parent error\n");
807 ret
= -LTTNG_ERR_FILTER_INVAL
;
811 ret
= filter_visitor_print_xml(ctx
, stdout
, 0);
814 fprintf(stderr
, "XML print error\n");
815 ret
= -LTTNG_ERR_FILTER_INVAL
;
820 dbg_printf("Generating IR... ");
822 ret
= filter_visitor_ir_generate(ctx
);
824 fprintf(stderr
, "Generate IR error\n");
825 ret
= -LTTNG_ERR_FILTER_INVAL
;
828 dbg_printf("done\n");
830 dbg_printf("Validating IR... ");
832 ret
= filter_visitor_ir_check_binary_op_nesting(ctx
);
834 ret
= -LTTNG_ERR_FILTER_INVAL
;
837 dbg_printf("done\n");
839 dbg_printf("Generating bytecode... ");
841 ret
= filter_visitor_bytecode_generate(ctx
);
843 fprintf(stderr
, "Generate bytecode error\n");
844 ret
= -LTTNG_ERR_FILTER_INVAL
;
847 dbg_printf("done\n");
848 dbg_printf("Size of bytecode generated: %u bytes.\n",
849 bytecode_get_len(&ctx
->bytecode
->b
));
851 lsm
.u
.enable
.bytecode_len
= sizeof(ctx
->bytecode
->b
)
852 + bytecode_get_len(&ctx
->bytecode
->b
);
853 lsm
.u
.enable
.expression_len
= strlen(filter_expression
) + 1;
856 varlen_data
= zmalloc(lsm
.u
.enable
.bytecode_len
857 + lsm
.u
.enable
.expression_len
858 + LTTNG_SYMBOL_NAME_LEN
* exclusion_count
);
860 ret
= -LTTNG_ERR_EXCLUSION_NOMEM
;
861 goto varlen_alloc_error
;
863 /* Put exclusion names first in the data */
864 while (exclusion_count
--) {
865 strncpy(varlen_data
+ LTTNG_SYMBOL_NAME_LEN
* exclusion_count
,
866 *(exclusion_list
+ exclusion_count
),
867 LTTNG_SYMBOL_NAME_LEN
);
869 /* Add filter expression next */
870 if (lsm
.u
.enable
.expression_len
!= 0) {
872 + LTTNG_SYMBOL_NAME_LEN
* lsm
.u
.enable
.exclusion_count
,
874 lsm
.u
.enable
.expression_len
);
876 /* Add filter bytecode next */
877 if (lsm
.u
.enable
.bytecode_len
!= 0) {
879 + LTTNG_SYMBOL_NAME_LEN
* lsm
.u
.enable
.exclusion_count
880 + lsm
.u
.enable
.expression_len
,
882 lsm
.u
.enable
.bytecode_len
);
885 ret
= lttng_ctl_ask_sessiond_varlen(&lsm
, varlen_data
,
886 (LTTNG_SYMBOL_NAME_LEN
* lsm
.u
.enable
.exclusion_count
) +
887 lsm
.u
.enable
.bytecode_len
+ lsm
.u
.enable
.expression_len
,
892 if (filter_expression
) {
893 filter_bytecode_free(ctx
);
895 filter_parser_ctx_free(ctx
);
896 if (fclose(fmem
) != 0) {
904 filter_bytecode_free(ctx
);
906 filter_parser_ctx_free(ctx
);
908 if (fclose(fmem
) != 0) {
916 * Disable event(s) of a channel and domain.
917 * If no event name is specified, all events are disabled.
918 * If no channel name is specified, the default 'channel0' is used.
919 * Returns size of returned session payload data or a negative error code.
921 int lttng_disable_event(struct lttng_handle
*handle
, const char *name
,
922 const char *channel_name
)
924 struct lttcomm_session_msg lsm
;
926 if (handle
== NULL
) {
927 return -LTTNG_ERR_INVALID
;
930 memset(&lsm
, 0, sizeof(lsm
));
932 /* If no channel name, send empty string. */
933 if (channel_name
== NULL
) {
934 lttng_ctl_copy_string(lsm
.u
.disable
.channel_name
, "",
935 sizeof(lsm
.u
.disable
.channel_name
));
937 lttng_ctl_copy_string(lsm
.u
.disable
.channel_name
, channel_name
,
938 sizeof(lsm
.u
.disable
.channel_name
));
941 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
944 lttng_ctl_copy_string(lsm
.u
.disable
.name
, name
,
945 sizeof(lsm
.u
.disable
.name
));
946 lsm
.cmd_type
= LTTNG_DISABLE_EVENT
;
948 lsm
.cmd_type
= LTTNG_DISABLE_ALL_EVENT
;
951 lttng_ctl_copy_string(lsm
.session
.name
, handle
->session_name
,
952 sizeof(lsm
.session
.name
));
954 return lttng_ctl_ask_sessiond(&lsm
, NULL
);
958 * Enable channel per domain
959 * Returns size of returned session payload data or a negative error code.
961 int lttng_enable_channel(struct lttng_handle
*handle
,
962 struct lttng_channel
*chan
)
964 struct lttcomm_session_msg lsm
;
967 * NULL arguments are forbidden. No default values.
969 if (handle
== NULL
|| chan
== NULL
) {
970 return -LTTNG_ERR_INVALID
;
973 memset(&lsm
, 0, sizeof(lsm
));
975 memcpy(&lsm
.u
.channel
.chan
, chan
, sizeof(lsm
.u
.channel
.chan
));
977 lsm
.cmd_type
= LTTNG_ENABLE_CHANNEL
;
979 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
981 lttng_ctl_copy_string(lsm
.session
.name
, handle
->session_name
,
982 sizeof(lsm
.session
.name
));
984 return lttng_ctl_ask_sessiond(&lsm
, NULL
);
988 * All tracing will be stopped for registered events of the channel.
989 * Returns size of returned session payload data or a negative error code.
991 int lttng_disable_channel(struct lttng_handle
*handle
, const char *name
)
993 struct lttcomm_session_msg lsm
;
995 /* Safety check. Both are mandatory */
996 if (handle
== NULL
|| name
== NULL
) {
997 return -LTTNG_ERR_INVALID
;
1000 memset(&lsm
, 0, sizeof(lsm
));
1002 lsm
.cmd_type
= LTTNG_DISABLE_CHANNEL
;
1004 lttng_ctl_copy_string(lsm
.u
.disable
.channel_name
, name
,
1005 sizeof(lsm
.u
.disable
.channel_name
));
1007 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
1009 lttng_ctl_copy_string(lsm
.session
.name
, handle
->session_name
,
1010 sizeof(lsm
.session
.name
));
1012 return lttng_ctl_ask_sessiond(&lsm
, NULL
);
1016 * Lists all available tracepoints of domain.
1017 * Sets the contents of the events array.
1018 * Returns the number of lttng_event entries in events;
1019 * on error, returns a negative value.
1021 int lttng_list_tracepoints(struct lttng_handle
*handle
,
1022 struct lttng_event
**events
)
1025 struct lttcomm_session_msg lsm
;
1027 if (handle
== NULL
) {
1028 return -LTTNG_ERR_INVALID
;
1031 memset(&lsm
, 0, sizeof(lsm
));
1032 lsm
.cmd_type
= LTTNG_LIST_TRACEPOINTS
;
1033 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
1035 ret
= lttng_ctl_ask_sessiond(&lsm
, (void **) events
);
1040 return ret
/ sizeof(struct lttng_event
);
1044 * Lists all available tracepoint fields of domain.
1045 * Sets the contents of the event field array.
1046 * Returns the number of lttng_event_field entries in events;
1047 * on error, returns a negative value.
1049 int lttng_list_tracepoint_fields(struct lttng_handle
*handle
,
1050 struct lttng_event_field
**fields
)
1053 struct lttcomm_session_msg lsm
;
1055 if (handle
== NULL
) {
1056 return -LTTNG_ERR_INVALID
;
1059 memset(&lsm
, 0, sizeof(lsm
));
1060 lsm
.cmd_type
= LTTNG_LIST_TRACEPOINT_FIELDS
;
1061 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
1063 ret
= lttng_ctl_ask_sessiond(&lsm
, (void **) fields
);
1068 return ret
/ sizeof(struct lttng_event_field
);
1072 * Returns a human readable string describing
1073 * the error code (a negative value).
1075 const char *lttng_strerror(int code
)
1077 return error_get_str(code
);
1081 * Create a brand new session using name and url for destination.
1083 * Returns LTTNG_OK on success or a negative error code.
1085 int lttng_create_session(const char *name
, const char *url
)
1089 struct lttcomm_session_msg lsm
;
1090 struct lttng_uri
*uris
= NULL
;
1093 return -LTTNG_ERR_INVALID
;
1096 memset(&lsm
, 0, sizeof(lsm
));
1098 lsm
.cmd_type
= LTTNG_CREATE_SESSION
;
1099 lttng_ctl_copy_string(lsm
.session
.name
, name
, sizeof(lsm
.session
.name
));
1101 /* There should never be a data URL */
1102 size
= uri_parse_str_urls(url
, NULL
, &uris
);
1104 return -LTTNG_ERR_INVALID
;
1107 lsm
.u
.uri
.size
= size
;
1109 ret
= lttng_ctl_ask_sessiond_varlen(&lsm
, uris
,
1110 sizeof(struct lttng_uri
) * size
, NULL
);
1117 * Destroy session using name.
1118 * Returns size of returned session payload data or a negative error code.
1120 int lttng_destroy_session(const char *session_name
)
1122 struct lttcomm_session_msg lsm
;
1124 if (session_name
== NULL
) {
1125 return -LTTNG_ERR_INVALID
;
1128 memset(&lsm
, 0, sizeof(lsm
));
1129 lsm
.cmd_type
= LTTNG_DESTROY_SESSION
;
1131 lttng_ctl_copy_string(lsm
.session
.name
, session_name
,
1132 sizeof(lsm
.session
.name
));
1134 return lttng_ctl_ask_sessiond(&lsm
, NULL
);
1138 * Ask the session daemon for all available sessions.
1139 * Sets the contents of the sessions array.
1140 * Returns the number of lttng_session entries in sessions;
1141 * on error, returns a negative value.
1143 int lttng_list_sessions(struct lttng_session
**sessions
)
1146 struct lttcomm_session_msg lsm
;
1148 memset(&lsm
, 0, sizeof(lsm
));
1149 lsm
.cmd_type
= LTTNG_LIST_SESSIONS
;
1150 ret
= lttng_ctl_ask_sessiond(&lsm
, (void**) sessions
);
1155 return ret
/ sizeof(struct lttng_session
);
1159 * Ask the session daemon for all available domains of a session.
1160 * Sets the contents of the domains array.
1161 * Returns the number of lttng_domain entries in domains;
1162 * on error, returns a negative value.
1164 int lttng_list_domains(const char *session_name
,
1165 struct lttng_domain
**domains
)
1168 struct lttcomm_session_msg lsm
;
1170 if (session_name
== NULL
) {
1171 return -LTTNG_ERR_INVALID
;
1174 memset(&lsm
, 0, sizeof(lsm
));
1175 lsm
.cmd_type
= LTTNG_LIST_DOMAINS
;
1177 lttng_ctl_copy_string(lsm
.session
.name
, session_name
,
1178 sizeof(lsm
.session
.name
));
1180 ret
= lttng_ctl_ask_sessiond(&lsm
, (void**) domains
);
1185 return ret
/ sizeof(struct lttng_domain
);
1189 * Ask the session daemon for all available channels of a session.
1190 * Sets the contents of the channels array.
1191 * Returns the number of lttng_channel entries in channels;
1192 * on error, returns a negative value.
1194 int lttng_list_channels(struct lttng_handle
*handle
,
1195 struct lttng_channel
**channels
)
1198 struct lttcomm_session_msg lsm
;
1200 if (handle
== NULL
) {
1201 return -LTTNG_ERR_INVALID
;
1204 memset(&lsm
, 0, sizeof(lsm
));
1205 lsm
.cmd_type
= LTTNG_LIST_CHANNELS
;
1206 lttng_ctl_copy_string(lsm
.session
.name
, handle
->session_name
,
1207 sizeof(lsm
.session
.name
));
1209 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
1211 ret
= lttng_ctl_ask_sessiond(&lsm
, (void**) channels
);
1216 return ret
/ sizeof(struct lttng_channel
);
1220 * Ask the session daemon for all available events of a session channel.
1221 * Sets the contents of the events array.
1222 * Returns the number of lttng_event entries in events;
1223 * on error, returns a negative value.
1225 int lttng_list_events(struct lttng_handle
*handle
,
1226 const char *channel_name
, struct lttng_event
**events
)
1229 struct lttcomm_session_msg lsm
;
1231 /* Safety check. An handle and channel name are mandatory */
1232 if (handle
== NULL
|| channel_name
== NULL
) {
1233 return -LTTNG_ERR_INVALID
;
1236 memset(&lsm
, 0, sizeof(lsm
));
1237 lsm
.cmd_type
= LTTNG_LIST_EVENTS
;
1238 lttng_ctl_copy_string(lsm
.session
.name
, handle
->session_name
,
1239 sizeof(lsm
.session
.name
));
1240 lttng_ctl_copy_string(lsm
.u
.list
.channel_name
, channel_name
,
1241 sizeof(lsm
.u
.list
.channel_name
));
1243 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
1245 ret
= lttng_ctl_ask_sessiond(&lsm
, (void**) events
);
1250 return ret
/ sizeof(struct lttng_event
);
1254 * Sets the tracing_group variable with name.
1255 * This function allocates memory pointed to by tracing_group.
1256 * On success, returns 0, on error, returns -1 (null name) or -ENOMEM.
1258 int lttng_set_tracing_group(const char *name
)
1261 return -LTTNG_ERR_INVALID
;
1264 if (asprintf(&tracing_group
, "%s", name
) < 0) {
1265 return -LTTNG_ERR_FATAL
;
1272 * Returns size of returned session payload data or a negative error code.
1274 int lttng_calibrate(struct lttng_handle
*handle
,
1275 struct lttng_calibrate
*calibrate
)
1277 struct lttcomm_session_msg lsm
;
1279 /* Safety check. NULL pointer are forbidden */
1280 if (handle
== NULL
|| calibrate
== NULL
) {
1281 return -LTTNG_ERR_INVALID
;
1284 memset(&lsm
, 0, sizeof(lsm
));
1285 lsm
.cmd_type
= LTTNG_CALIBRATE
;
1286 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
1288 memcpy(&lsm
.u
.calibrate
, calibrate
, sizeof(lsm
.u
.calibrate
));
1290 return lttng_ctl_ask_sessiond(&lsm
, NULL
);
1294 * Set default channel attributes.
1295 * If either or both of the arguments are null, attr content is zeroe'd.
1297 void lttng_channel_set_default_attr(struct lttng_domain
*domain
,
1298 struct lttng_channel_attr
*attr
)
1301 if (attr
== NULL
|| domain
== NULL
) {
1305 memset(attr
, 0, sizeof(struct lttng_channel_attr
));
1307 /* Same for all domains. */
1308 attr
->overwrite
= DEFAULT_CHANNEL_OVERWRITE
;
1309 attr
->tracefile_size
= DEFAULT_CHANNEL_TRACEFILE_SIZE
;
1310 attr
->tracefile_count
= DEFAULT_CHANNEL_TRACEFILE_COUNT
;
1312 switch (domain
->type
) {
1313 case LTTNG_DOMAIN_KERNEL
:
1314 attr
->switch_timer_interval
= DEFAULT_KERNEL_CHANNEL_SWITCH_TIMER
;
1315 attr
->read_timer_interval
= DEFAULT_KERNEL_CHANNEL_READ_TIMER
;
1316 attr
->subbuf_size
= default_get_kernel_channel_subbuf_size();
1317 attr
->num_subbuf
= DEFAULT_KERNEL_CHANNEL_SUBBUF_NUM
;
1318 attr
->output
= DEFAULT_KERNEL_CHANNEL_OUTPUT
;
1320 case LTTNG_DOMAIN_UST
:
1321 switch (domain
->buf_type
) {
1322 case LTTNG_BUFFER_PER_UID
:
1323 attr
->subbuf_size
= default_get_ust_uid_channel_subbuf_size();
1324 attr
->num_subbuf
= DEFAULT_UST_UID_CHANNEL_SUBBUF_NUM
;
1325 attr
->output
= DEFAULT_UST_UID_CHANNEL_OUTPUT
;
1326 attr
->switch_timer_interval
= DEFAULT_UST_UID_CHANNEL_SWITCH_TIMER
;
1327 attr
->read_timer_interval
= DEFAULT_UST_UID_CHANNEL_READ_TIMER
;
1329 case LTTNG_BUFFER_PER_PID
:
1331 attr
->subbuf_size
= default_get_ust_pid_channel_subbuf_size();
1332 attr
->num_subbuf
= DEFAULT_UST_PID_CHANNEL_SUBBUF_NUM
;
1333 attr
->output
= DEFAULT_UST_PID_CHANNEL_OUTPUT
;
1334 attr
->switch_timer_interval
= DEFAULT_UST_PID_CHANNEL_SWITCH_TIMER
;
1335 attr
->read_timer_interval
= DEFAULT_UST_PID_CHANNEL_READ_TIMER
;
1339 /* Default behavior: leave set to 0. */
1345 * Check if session daemon is alive.
1347 * Return 1 if alive or 0 if not.
1348 * On error returns a negative value.
1350 int lttng_session_daemon_alive(void)
1354 ret
= set_session_daemon_path();
1360 if (*sessiond_sock_path
== '\0') {
1362 * No socket path set. Weird error which means the constructor was not
1368 ret
= try_connect_sessiond(sessiond_sock_path
);
1379 * Set URL for a consumer for a session and domain.
1381 * Return 0 on success, else a negative value.
1383 int lttng_set_consumer_url(struct lttng_handle
*handle
,
1384 const char *control_url
, const char *data_url
)
1388 struct lttcomm_session_msg lsm
;
1389 struct lttng_uri
*uris
= NULL
;
1391 if (handle
== NULL
|| (control_url
== NULL
&& data_url
== NULL
)) {
1392 return -LTTNG_ERR_INVALID
;
1395 memset(&lsm
, 0, sizeof(lsm
));
1397 lsm
.cmd_type
= LTTNG_SET_CONSUMER_URI
;
1399 lttng_ctl_copy_string(lsm
.session
.name
, handle
->session_name
,
1400 sizeof(lsm
.session
.name
));
1401 lttng_ctl_copy_lttng_domain(&lsm
.domain
, &handle
->domain
);
1403 size
= uri_parse_str_urls(control_url
, data_url
, &uris
);
1405 return -LTTNG_ERR_INVALID
;
1408 lsm
.u
.uri
.size
= size
;
1410 ret
= lttng_ctl_ask_sessiond_varlen(&lsm
, uris
,
1411 sizeof(struct lttng_uri
) * size
, NULL
);
1420 int lttng_enable_consumer(struct lttng_handle
*handle
)
1428 int lttng_disable_consumer(struct lttng_handle
*handle
)
1434 * This is an extension of create session that is ONLY and SHOULD only be used
1435 * by the lttng command line program. It exists to avoid using URI parsing in
1438 * We need the date and time for the trace path subdirectory for the case where
1439 * the user does NOT define one using either -o or -U. Using the normal
1440 * lttng_create_session API call, we have no clue on the session daemon side if
1441 * the URL was generated automatically by the client or define by the user.
1443 * So this function "wrapper" is hidden from the public API, takes the datetime
1444 * string and appends it if necessary to the URI subdirectory before sending it
1445 * to the session daemon.
1447 * With this extra function, the lttng_create_session call behavior is not
1448 * changed and the timestamp is appended to the URI on the session daemon side
1451 int _lttng_create_session_ext(const char *name
, const char *url
,
1452 const char *datetime
)
1456 struct lttcomm_session_msg lsm
;
1457 struct lttng_uri
*uris
= NULL
;
1459 if (name
== NULL
|| datetime
== NULL
) {
1460 return -LTTNG_ERR_INVALID
;
1463 memset(&lsm
, 0, sizeof(lsm
));
1465 lsm
.cmd_type
= LTTNG_CREATE_SESSION
;
1466 lttng_ctl_copy_string(lsm
.session
.name
, name
, sizeof(lsm
.session
.name
));
1468 /* There should never be a data URL */
1469 size
= uri_parse_str_urls(url
, NULL
, &uris
);
1471 ret
= -LTTNG_ERR_INVALID
;
1475 lsm
.u
.uri
.size
= size
;
1477 if (size
> 0 && uris
[0].dtype
!= LTTNG_DST_PATH
&& strlen(uris
[0].subdir
) == 0) {
1478 /* Don't append datetime if the name was automatically created. */
1479 if (strncmp(name
, DEFAULT_SESSION_NAME
"-",
1480 strlen(DEFAULT_SESSION_NAME
) + 1)) {
1481 ret
= snprintf(uris
[0].subdir
, sizeof(uris
[0].subdir
), "%s-%s",
1484 ret
= snprintf(uris
[0].subdir
, sizeof(uris
[0].subdir
), "%s", name
);
1487 PERROR("snprintf uri subdir");
1488 ret
= -LTTNG_ERR_FATAL
;
1493 ret
= lttng_ctl_ask_sessiond_varlen(&lsm
, uris
,
1494 sizeof(struct lttng_uri
) * size
, NULL
);
1502 * For a given session name, this call checks if the data is ready to be read
1503 * or is still being extracted by the consumer(s) hence not ready to be used by
1506 int lttng_data_pending(const char *session_name
)
1509 struct lttcomm_session_msg lsm
;
1511 if (session_name
== NULL
) {
1512 return -LTTNG_ERR_INVALID
;
1515 memset(&lsm
, 0, sizeof(lsm
));
1516 lsm
.cmd_type
= LTTNG_DATA_PENDING
;
1518 lttng_ctl_copy_string(lsm
.session
.name
, session_name
,
1519 sizeof(lsm
.session
.name
));
1521 ret
= lttng_ctl_ask_sessiond(&lsm
, NULL
);
1524 * The lttng_ctl_ask_sessiond function negate the return code if it's not
1525 * LTTNG_OK so getting -1 means that the reply ret_code was 1 thus meaning
1526 * that the data is available. Yes it is hackish but for now this is the
1537 * Create a session exclusively used for snapshot.
1539 * Returns LTTNG_OK on success or a negative error code.
1541 int lttng_create_session_snapshot(const char *name
, const char *snapshot_url
)
1545 struct lttcomm_session_msg lsm
;
1546 struct lttng_uri
*uris
= NULL
;
1549 return -LTTNG_ERR_INVALID
;
1552 memset(&lsm
, 0, sizeof(lsm
));
1554 lsm
.cmd_type
= LTTNG_CREATE_SESSION_SNAPSHOT
;
1555 lttng_ctl_copy_string(lsm
.session
.name
, name
, sizeof(lsm
.session
.name
));
1557 size
= uri_parse_str_urls(snapshot_url
, NULL
, &uris
);
1559 return -LTTNG_ERR_INVALID
;
1562 lsm
.u
.uri
.size
= size
;
1564 ret
= lttng_ctl_ask_sessiond_varlen(&lsm
, uris
,
1565 sizeof(struct lttng_uri
) * size
, NULL
);
1572 * Create a session exclusively used for live.
1574 * Returns LTTNG_OK on success or a negative error code.
1576 int lttng_create_session_live(const char *name
, const char *url
,
1577 unsigned int timer_interval
)
1581 struct lttcomm_session_msg lsm
;
1582 struct lttng_uri
*uris
= NULL
;
1585 return -LTTNG_ERR_INVALID
;
1588 memset(&lsm
, 0, sizeof(lsm
));
1590 lsm
.cmd_type
= LTTNG_CREATE_SESSION_LIVE
;
1591 lttng_ctl_copy_string(lsm
.session
.name
, name
, sizeof(lsm
.session
.name
));
1594 size
= uri_parse_str_urls(url
, NULL
, &uris
);
1596 ret
= -LTTNG_ERR_INVALID
;
1600 /* file:// is not accepted for live session. */
1601 if (uris
[0].dtype
== LTTNG_DST_PATH
) {
1602 ret
= -LTTNG_ERR_INVALID
;
1609 lsm
.u
.session_live
.nb_uri
= size
;
1610 lsm
.u
.session_live
.timer_interval
= timer_interval
;
1612 ret
= lttng_ctl_ask_sessiond_varlen(&lsm
, uris
,
1613 sizeof(struct lttng_uri
) * size
, NULL
);
1623 static void __attribute__((constructor
)) init()
1625 /* Set default session group */
1626 lttng_set_tracing_group(DEFAULT_TRACING_GROUP
);
1632 static void __attribute__((destructor
)) lttng_ctl_exit()
1634 free(tracing_group
);